Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, touch sensor panels, joysticks, touch pads, touch screens and the like. Touch screens and touch pads, in particular, are becoming increasingly popular because of their ease and versatility of operation as well as their declining price. Touch screens can include a touch sensor panel, which can be a clear panel with a touch sensitive surface, and a display device that can be positioned behind the panel so that the touch sensitive surface can substantially cover the viewable area of the display device. Touch screens can allow a user to perform various functions by touching the touch sensor panel using one or more fingers, a stylus or other object at a location dictated by a user interface (UI) comprising virtual buttons, keys, bars, displays, and other elements, being displayed by the display device. In general, touch screens can recognize a touch event and the position of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the display appearing at the time of the touch event, and thereafter can perform one or more actions based on the touch event.
Similarly, touch pads can include a touch sensor panel having a touch sensitive surface. Touch pads can allow a user to perform various functions by touching the touch sensor panel using one or more fingers, a stylus or other object at a location dictated by a UI comprising a touch space. In general, touch pads can recognize a touch event and the position of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the position of the touch event, and thereafter can perform one or more actions based on the touch event.
Touch screens and touch pads can typically have a smooth fixed outer surface through which inputs/outputs can be made. For example, the outer surface can act as an input mechanism that receives touch inputs such as taps, slides and other gestures. With touch screens, the outer surface can further act as a window for displaying text and graphics that change during use. In most cases, the physical surfaces of these devices can be smooth and fixed. In some cases, they can be flat and planar. They generally do not include tactile features like buttons and therefore can be used across many modes, applications or platforms. However, because these surfaces generally do not include tactile features, the user can have a difficult time locating UI elements without looking at the visual screen to ensure that the desired location is touched.